ACPI / PNP: Avoid conflicting resource reservations (0f1b414d) · Commits · 戴 / test

drivers/acpi/osl.c

+1 −5

Original line number	Diff line number	Diff line
		@@ -175,11 +175,7 @@ static void __init acpi_request_region (struct acpi_generic_address *gas,
		if (!addr \|\| !length)
		return;

		/* Resources are never freed */
		if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_IO)
		request_region(addr, length, desc);
		else if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
		request_mem_region(addr, length, desc);
		acpi_reserve_region(addr, length, gas->space_id, 0, desc);
		}

		static void __init acpi_reserve_resources(void)

drivers/acpi/resource.c

+160 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,7 @@
		#include <linux/device.h>
		#include <linux/export.h>
		#include <linux/ioport.h>
		#include <linux/list.h>
		#include <linux/slab.h>

		#ifdef CONFIG_X86
		@@ -621,3 +622,162 @@ int acpi_dev_filter_resource_type(struct acpi_resource *ares,
		return (type & types) ? 0 : 1;
		}
		EXPORT_SYMBOL_GPL(acpi_dev_filter_resource_type);

		struct reserved_region {
		struct list_head node;
		u64 start;
		u64 end;
		};

		static LIST_HEAD(reserved_io_regions);
		static LIST_HEAD(reserved_mem_regions);

		static int request_range(u64 start, u64 end, u8 space_id, unsigned long flags,
		char *desc)
		{
		unsigned int length = end - start + 1;
		struct resource *res;

		res = space_id == ACPI_ADR_SPACE_SYSTEM_IO ?
		request_region(start, length, desc) :
		request_mem_region(start, length, desc);
		if (!res)
		return -EIO;

		res->flags &= ~flags;
		return 0;
		}

		static int add_region_before(u64 start, u64 end, u8 space_id,
		unsigned long flags, char *desc,
		struct list_head *head)
		{
		struct reserved_region *reg;
		int error;

		reg = kmalloc(sizeof(*reg), GFP_KERNEL);
		if (!reg)
		return -ENOMEM;

		error = request_range(start, end, space_id, flags, desc);
		if (error)
		return error;

		reg->start = start;
		reg->end = end;
		list_add_tail(&reg->node, head);
		return 0;
		}

		/**
		* acpi_reserve_region - Reserve an I/O or memory region as a system resource.
		* @start: Starting address of the region.
		* @length: Length of the region.
		* @space_id: Identifier of address space to reserve the region from.
		* @flags: Resource flags to clear for the region after requesting it.
		* @desc: Region description (for messages).
		*
		* Reserve an I/O or memory region as a system resource to prevent others from
		* using it. If the new region overlaps with one of the regions (in the given
		* address space) already reserved by this routine, only the non-overlapping
		* parts of it will be reserved.
		*
		* Returned is either 0 (success) or a negative error code indicating a resource
		* reservation problem. It is the code of the first encountered error, but the
		* routine doesn't abort until it has attempted to request all of the parts of
		* the new region that don't overlap with other regions reserved previously.
		*
		* The resources requested by this routine are never released.
		*/
		int acpi_reserve_region(u64 start, unsigned int length, u8 space_id,
		unsigned long flags, char *desc)
		{
		struct list_head *regions;
		struct reserved_region *reg;
		u64 end = start + length - 1;
		int ret = 0, error = 0;

		if (space_id == ACPI_ADR_SPACE_SYSTEM_IO)
		regions = &reserved_io_regions;
		else if (space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
		regions = &reserved_mem_regions;
		else
		return -EINVAL;

		if (list_empty(regions))
		return add_region_before(start, end, space_id, flags, desc, regions);

		list_for_each_entry(reg, regions, node)
		if (reg->start == end + 1) {
		/* The new region can be prepended to this one. */
		ret = request_range(start, end, space_id, flags, desc);
		if (!ret)
		reg->start = start;

		return ret;
		} else if (reg->start > end) {
		/* No overlap. Add the new region here and get out. */
		return add_region_before(start, end, space_id, flags,
		desc, &reg->node);
		} else if (reg->end == start - 1) {
		goto combine;
		} else if (reg->end >= start) {
		goto overlap;
		}

		/* The new region goes after the last existing one. */
		return add_region_before(start, end, space_id, flags, desc, regions);

		overlap:
		/*
		* The new region overlaps an existing one.
		*
		* The head part of the new region immediately preceding the existing
		* overlapping one can be combined with it right away.
		*/
		if (reg->start > start) {
		error = request_range(start, reg->start - 1, space_id, flags, desc);
		if (error)
		ret = error;
		else
		reg->start = start;
		}

		combine:
		/*
		* The new region is adjacent to an existing one. If it extends beyond
		* that region all the way to the next one, it is possible to combine
		* all three of them.
		*/
		while (reg->end < end) {
		struct reserved_region *next = NULL;
		u64 a = reg->end + 1, b = end;

		if (!list_is_last(&reg->node, regions)) {
		next = list_next_entry(reg, node);
		if (next->start <= end)
		b = next->start - 1;
		}
		error = request_range(a, b, space_id, flags, desc);
		if (!error) {
		if (next && next->start == b + 1) {
		reg->end = next->end;
		list_del(&next->node);
		kfree(next);
		} else {
		reg->end = end;
		break;
		}
		} else if (next) {
		if (!ret)
		ret = error;

		reg = next;
		} else {
		break;
		}
		}

		return ret ? ret : error;
		}
		EXPORT_SYMBOL_GPL(acpi_reserve_region);

drivers/pnp/system.c

+26 −9

Original line number	Diff line number	Diff line
		@@ -7,6 +7,7 @@
		* Bjorn Helgaas <bjorn.helgaas@hp.com>
		*/

		#include <linux/acpi.h>
		#include <linux/pnp.h>
		#include <linux/device.h>
		#include <linux/init.h>
		@@ -22,25 +23,41 @@ static const struct pnp_device_id pnp_dev_table[] = {
		{"", 0}
		};

		#ifdef CONFIG_ACPI
		static bool __reserve_range(u64 start, unsigned int length, bool io, char *desc)
		{
		u8 space_id = io ? ACPI_ADR_SPACE_SYSTEM_IO : ACPI_ADR_SPACE_SYSTEM_MEMORY;
		return !acpi_reserve_region(start, length, space_id, IORESOURCE_BUSY, desc);
		}
		#else
		static bool __reserve_range(u64 start, unsigned int length, bool io, char *desc)
		{
		struct resource *res;

		res = io ? request_region(start, length, desc) :
		request_mem_region(start, length, desc);
		if (res) {
		res->flags &= ~IORESOURCE_BUSY;
		return true;
		}
		return false;
		}
		#endif

		static void reserve_range(struct pnp_dev dev, struct resource r, int port)
		{
		char *regionid;
		const char *pnpid = dev_name(&dev->dev);
		resource_size_t start = r->start, end = r->end;
		struct resource *res;
		bool reserved;

		regionid = kmalloc(16, GFP_KERNEL);
		if (!regionid)
		return;

		snprintf(regionid, 16, "pnp %s", pnpid);
		if (port)
		res = request_region(start, end - start + 1, regionid);
		else
		res = request_mem_region(start, end - start + 1, regionid);
		if (res)
		res->flags &= ~IORESOURCE_BUSY;
		else
		reserved = __reserve_range(start, end - start + 1, !!port, regionid);
		if (!reserved)
		kfree(regionid);

		/*
		@@ -49,7 +66,7 @@ static void reserve_range(struct pnp_dev dev, struct resource r, int port)
		* have double reservations.
		*/
		dev_info(&dev->dev, "%pR %s reserved\n", r,
		res ? "has been" : "could not be");
		reserved ? "has been" : "could not be");
		}

		static void reserve_resources_of_dev(struct pnp_dev *dev)

include/linux/acpi.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -332,6 +332,9 @@ int acpi_check_region(resource_size_t start, resource_size_t n,

		int acpi_resources_are_enforced(void);

		int acpi_reserve_region(u64 start, unsigned int length, u8 space_id,
		unsigned long flags, char *desc);

		#ifdef CONFIG_HIBERNATION
		void __init acpi_no_s4_hw_signature(void);
		#endif
		@@ -525,6 +528,13 @@ static inline int acpi_check_region(resource_size_t start, resource_size_t n,
		return 0;
		}

		static inline int acpi_reserve_region(u64 start, unsigned int length,
		u8 space_id, unsigned long flags,
		char *desc)
		{
		return -ENXIO;
		}

		struct acpi_table_header;
		static inline int acpi_table_parse(char *id,
		int (handler)(struct acpi_table_header ))

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